Phenylmercuric glycollate and a process of making it



Patented May 2, 1939 UNITED STATES PATENT OFFICE PHENYIMERCURICGLYCOLLATE AND A PROCESS OF MAKING IT Ralph P. Perkins, Midland, Mich.,assignor to The Dow Chemical Company, Midland, Mich., a corporation ofMichigan 5 Claims.

This invention concerns phenylmercuric glycollate, a new compound usefulas a germicide, disinfectant, fungicide, etc., and a method of makingthe same.

In a copending application Serial No. 683,017, filed July 31, 1933, ofwhich the present application is a division, I have disclosed a numberof phenylmercuric salts of aliphatic hydroxycarboxylic acids, togetherwith a method of preparing the same, and have claimed the phenylmercuricsalts of aliphatic hydroxy-poly-carboxylic acids. The presentapplication concerns the phenylmercuric salt of ahydroxy-monocarlocgylic acid, specifically phenylmercuric glycol-Phenylmercuric glycollate may be prepared by reacting phenylmercurichydroxide directly with glycollic acid. The phenylmercuric hydroxide maybe obtained from any source, for instance from benzene by the followingprocedure: A mixture of mercuric oxide with more than its molecularequivalent each of benzene and of glacial acetic acid is heated tobetween and 120 C. until a sample of the mixture is found by analysis tobe substantially free of mercuric ions. The mixture is then cooled toabout room temperature or lower and filtered to remove insolubleimpurities, e. g., poly-acetoxymercuri-benzenes. The excess of benzeneis removed from the filtrate by distillation leaving as residue asolution or mixture of phenylmercuric acetate in acetic acid. The aceticacid is preferably, although not necessarily, removed by steamdistillation. The residual aqueous solution or mixture of phenylmercuricacetate is treated at between 80 and C. with sufficient watersolublehydroxide, e. g., sodium hydroxide, potassium hydroxide, bariumhydroxide, etc., to convert the phenylmercuric acetate intophenylmercuric hydroxide. The latter is removed by filtration and washedwith water.

In place of acetic acid other lower aliphatic acids, e. g., propionicacid, butyric acid, etc., may be employed in the above describedprocedure for the preparation of phenylmercuric hydroxide.

Phenylmercuric hydroxide prepared as described above or otherwise issuspended or dissolved in a substantially inert liquid, e. g., water,alcohol, etc. The resultant mixture is treated with sufficient glycollicacid to neutralize the phenylmercuric hydroxide or with an excess of theacid, if desired, the mixture preferably, although not necessarily,being stirred and heated to facilitate the neutralization. After thereaction is completed, the phenylmercuric glycollate is separated fromthe mixture by crystallization, by evaporation of the solvent, orotherwise,

and may be purified by usual precedure. The product is obtained inexcellent yield and as a nearly pure compound.

Example 5 To a suspension of 6 grams (0.0204 mol) of phenylmercurichydroxide in 50 cubic centimeters of water was added 2 grams (0.0263mol) of glycollic acid, the mixture heated on a steam bath for one hourwith occasional stirring, after 10 which it was heated under reflux forabout three minutes and then cooled to room temperature to crystallizethe phenylmercuric glycollate product. The latter is filtered from themixture, washed with water, and dried. There 15 was obtained 6.4 grams(0.0181 mol) of white crystalline phenylmercuric glycollate. The productmelts at approximately 172.5-173 C. with decomposition and has probablythe formula,

In place of phenylmercuric hydroxide, phenylmercuric carbonate or infact any inorganic phenylmercuric base of strength sufiicient to re- 25act with glycollic acid may be employed as a reactant in preparingphenylmercuric glycollate by the present method. However, I prefer toemploy phenylmercuric hydroxide rather than the corresponding carbonateas a reactant since foaming usually occurs when the carbonate is used.

Other modes of applying the principle of my invention may be employedinstead of those explained, change being made as regards the method orcompounds herein disclosed, provided the steps or compounds stated byany of the following claims or the equivalent of such stated steps orcompounds be employed.

I therefore particularly point out and distinctly claim as my invention:

1. The method of making phenlymercuric glycollate which comprisesreacting an inorganic phenylmercuric base with glycollic acid. 45

2. In a method of making phenylmercuric glycollate, the step whichconsists in reacting phenylmercuric hydroxide with glycollic acid.

3. In a method of making phenylmercuric glycollate, the step whichconsists in heating phenyl- 0 mercuric hydroxide with glycollic acid toa reaction' temperature in the presence of water.

4. Phenylmercuric glycollate.

5. Phenylmercuric glycollate, a crystalline compound melting atapproximately 172.5- 55 173 C. with decomposition.

RALPH P. PERKENS.

